The present invention relates to a liquid, shelf stable, ready to use baker's wash for coating bakery products such as rolls, breads or pie crusts. The wash is anaerobically packaged, such as in an aerosol container, and can be applied either before or after baking to provide a shine to bakery products.
Dry powder-type baker's washes are well known in the art. Early baker's washes consisted primarily of dried egg white and other ingredients, for example an agent to help the dried egg white dissolve in water. A typical prior art dried egg white baker's wash is disclosed in U.S. Pat. No. 4,115,592, Bergquist, et al., issued Sep. 19, 1978. The Bergquist, et al. patent discloses a process for preparing dried egg white having improved flow and water solubility characteristics. The process produces a powder comprised primarily of dried egg white and sugar. When it is desired to use the powdered composition on bakery goods, the powder is dissolved in water and applied by spraying, brushing or the like.
Egg white washes, like that of Bergquist, et al., are not shelf stable. Once the egg white powder is dissolved in the water, it has to be used within about 8 hours. After one day, the microorganism growth in the composition becomes prohibitively high such that the wash can no longer be employed on bakery goods. For this reason, it is necessary to make a fresh wash mixture every day. Since the liquid wash is a good medium for microorganism growth, manufacturers of egg white washes supplied bakeries with the product in a powder form which has a longer shelf life. However, contamination of the dry egg white powder often occurs since the powder is capable of supporting microorganism growth, especially in humid conditions, the egg white powder being very hydrophilic. Making a wash composition with contaminated egg white powder accelerates microorganism growth so that the wash quickly becomes unusable or, at best, the application lifetime of the wash is greatly reduced.
In response to widespread abuses by bakeries, health departments of various states outlawed baker's washes which employed egg white. Southern states having warm moist climates, such as Louisiana, have been particularly concerned with microorganism growth on food products. As a result, the southern states were generally the first ones to outlaw the use of baker's washes having an egg white composition.
In response to these health concerns, manufacturers started developing baker's washes which would produce a shine on bakery products, like the egg white composition wash, but which would not contain egg whites. Primarily, these dry formulations employed a protein substitute for the egg white, such as whey, and included additional ingredients necessary to make the whey perform in a manner similar to egg whites. While these protein compositions function very similarly to the egg white composition washes, they do not serve as a medium for microorganism growth in dry powder form. However, these non-egg white composition washes will support microorganism growth when the wash is in a liquid form. The washes must be used within one day of formulation in order to avoid significant microbiological contamination. Consequently, manufacturers produce non-egg white washes in powder form which have a more stable shelf life. Bakeries, then, have to add the powdered product to water to create the wash.
This has led to another problem: the failure of the end user to properly mix the correct proportion of the powder with the right amount of water. For example, in using the non-egg white composition manufactured by the assignee of the present invention, Baker's Bright, Inc., three different proportions of powder are employed based upon different applications. The before oven application for bread or rolls requires 3.25 ounces of the powder composition to be mixed with one quart of warm water (120.degree.-130.degree. F.), the after oven application for bread or rolls requires 2.5-3.25 ounces of the powder composition to be mixed with one quart of warm water. The before oven application for pies requires that 4 ounces of the powdered composition be mixed with one quart of warm water and, optionally, 2 ounces of vegetable oil. These different proportions and preparations of the powder sometimes confuse the baker, resulting in incorrectly formulated wash products and ultimately, bakery products which are less appealing to the consumer. The result is that dry powders are more useful in commercial baking where production formulation controls maintain wash uniformity.
Further, once the composition has been mixed with the warm water, it must set for about one-half hour in order to fully dissolve, obtain a uniform viscosity, and become homogeneous. Failure to permit the wash to set for the full time may result in a partially undissolved product having a lumpy composition which cannot be sprayed and which gives an undesirable appearance, even if brushed on the bakery product, because little or no shine is produced.
There was, therefore, a need for a baker's wash which does not contain any egg white, is ready to use in liquid form, and is shelf stable. By shelf stable, it is meant that the wash is capable of lasting at least 21 days after opening, with proper refrigeration. In effect, a shelf stable baker's wash must meet the minimum microorganism standards required by the FDA, both before and after opening. Once the microorganism level exceeds the minimum FDA requirements, the wash is no longer said to be shelf stable. These problems were effectively addressed by U.S. Pat. No. 4,863,751, Voss, issued Sep. 5, 1989, incorporated herein by reference, which describes a shelf stable ready to use liquid baker's wash composition. These compositions are exemplified as being useful in traditional aerobic packaging for bakery operations. The compositions are easy to apply and provide a desirable sheen to the finished baked product. The compositions are resistant to the growth of gram positive and gram negative bacteria, as well as yeast and mold. The composition utilizes a unique preservative system which comprises a mixture of methylparaben and propylparaben together with a suitable dispersing agent, such as a glycol.
In spite of the success, both technologically and commercially, of the product described in the Voss patent, there is a continuing desire to formulate baker's wash products in an anaerobic-type environment, such as in an aerosol spray. Such products would be very easy to dispense and use. However, packaging the wash composition in an anaerobic, rather than an aerobic, environment makes the composition vulnerable to different types of microorganisms, facultative anaerobic microorganisms, such as gram negative facultative anaerobic rods (Enterobacteriaceae, including Escherichia, Enterobacter and Salmonella), gram positive facultative anaerobic cocci (Micrococcaceae, including Staphylococcus, Enterococcus and Lactococcus) and gram positive facultative anaerobic nonsporulating regular rods (Lactobacillus). Since anaerobic microorganisms function physiologically in an entirely different manner from aerobic microorganisms, many preservative systems which are effective in an aerobic environment are not effective in an anaerobic context, particularly in the neutral pH range. Other preservatives, such as sodium benzoate, sorbates, propionates, sulfites and parabens are used in acidified or alcohol-based products to control microorganisms under aerobic, facultative and anaerobic conditions. However, none of these preservatives are known to function in the neutral product pH range.
Now, it has surprisingly been found that the methylparaben/propylparaben preservative system which is useful for baker's wash compositions in an aerobic context is also effective for use in such compositions in an anaerobic context, particularly in the neutral product pH range.